The present inventions are directed to using machine vision to locate balls, clubs/bats and person's using the clubs/bats.
Improving an athlete's opportunity to succeed may include providing approximate measurements of the athlete's movements and analyzing these measurements in light of general statistical data. Currently, an athlete, such as a golfer, may have their golf swing analyzed using one of many approaches involving cameras and lights to capture launch data for the golf ball (velocity, launch angle, spin) and the club data. Several disadvantages of these current prior art systems are overcome by the present invention. Specifically, none of these prior art methods and apparatuses provides the system which we have developed for several reasons:
1. The ball spin is found using a pattern of targets on the ball with special optical properties. (US Pat App 20070060410) Processing is described which depends upon these types of targets.
2. Other ball spin approaches are patented with specific marking patterns, which are different from the one we are currently using.
3. The acquisition setup is specific and different from what we are using. The approaches have differences in the geometry of the setup and acquired images and the timing and synchronization of the acquisition.
4. The approaches described all seem to presume the ability to get extremely high resolution, low noise data. Most of the approaches assume that with 2 “fixes” on the ball the spin can be computed. This is true, but with noisy data any single “fix” on the ball may lead to large errors. To solve this with better hardware can be quite expensive.
5. Most approaches seem to assume the ability to capture the data at high resolution and with a known and appropriate timing relationship. This can be done, but the cost of the resulting system may be extremely high.
U.S. Pat. No. 7,170,592 discloses a method for inspecting a curved object, such as a golf ball, including acquiring an image of a curved object using a detector, adjusting the image to minimize distortion and comparing the adjusted image to a predetermined adjusted master image. The novelty is in not requiring orientation of the object and the minimization of curvature distortion during measurement.
U.S. Pat. No. 7,143,639 discloses an improved portable, battery operated (power cell) Launch Monitor. The portable Launch Monitor includes a camera system, preferably four cameras, and at least two light systems for illuminating a field of view. The system includes data storage means and a display device. The system includes stored image references and recognizes images such as type of golf club and golf ball used during the measuring process. The system measures: club head speed, club head path angle, club head attack angle, club head loft, club head droop, club head face angle, club head face spin, club head droop spin, club head loft spin, and ball impact location on the golf club face, determines golf ball kinematic information such as ball speed, ball elevation angle, ball azimuth angle, ball back spin, ball rifle spin, ball side spin, and ball impact location on the golf club face. A video interface is provided to view and interface the resulting images and integrated analysis. The system may be network compatible to transfer data to a central server to display a golfer's characteristics, such as club characteristics, ball characteristics, ball trajectory, and equipment comparison. In other embodiments the network may be capable of transmitting transaction information, such as an equipment order, financial information of a purchaser, a shipping address, and salesperson information, to a central server. Additionally, the network may be capable of transmitting order confirmation information, updating software for the operating system, or transferring data to multiple data consumers.
U.S. Pat. App. No. 20070060410 discloses a method and apparatus for measuring golf ball launch conditions. This application has the same inventor as U.S. Pat. No. 7,143,639. The method includes acquiring an image of a field of view without a golf ball present and acquiring at least two images of a golf ball in motion within the field of view. The images are preferably based on one or more substantially circular markers that are included on the surface of the golf ball. After the images of the golf ball have been acquired, the image of the field of view is subtracted from each of the at least two images of the golf ball in motion. The location of a circular perimeter of the golf ball for each of the at least two images after the image of the field of view is subtracted may then be determined. The method also includes analyzing the circular perimeter in each of the at least two images to determine a position of the center of the golf ball in each image. The kinematic characteristics of the golf ball based on the substantially circular markers and the center of the golf ball in each of the at least two images may then be determined. A processor comprising a memory and software loaded thereon may be used to perform the subtracting and determining. Based on these steps, the kinematic characteristics of a golf ball such as side spin, back spin, trajectory, velocity, launch angle, and side angle may be calculated. An apparatus for determining the kinematics of a golf ball includes an illumination device selectively positioned to illuminate a field of view with light within a predetermined wavelength range, a golf ball having a surface that absorbs light within the predetermined wavelength range, and a background surface that reflects the light within the predetermined wavelength range. The background surface may comprise a high grey level surface in some embodiments. It may be desirable for the apparatus to also include a camera positioned to acquire one or more images of a field of view and a processor comprising memory and analyzing software loaded thereon. The software is preferably capable of analyzing the one or more acquired images to determine the position of the center of a golf ball.
U.S. Pat. App. No. 20070049393 discloses a method for predicting ball launch conditions. This application has the same inventor as U.S. Pat. No. 7,143,639 and U.S. Pat. App. No. 20070060410. The invention comprises a method for predicting a golfer's ball striking performance. The method includes determining a plurality of pre-impact swing properties for a golfer based on the golfer's swing with a golf club. The plurality of pre-impact swing properties may include, for example, an impact location, an orientation of a golf club head, and the golf club head speed. The slippage between the golf club and the golf ball is preferably determined. The slippage may be based on the plurality of ball properties, the plurality of club properties, and the plurality of pre-impact swing properties. The slippage may be determined by computing each time step, in microsecond time intervals, for a first slip period, a stick period, and a second slip period between the golf club and the golf ball. It is desired that each time step is based on at least a transverse force of the golf ball, a coefficient of friction of the golf ball, and a normal force of a golf ball. The pre-impact swing properties may be determined by having a golfer swing a golf club in front of a monitoring system. The golfer may swing the club any desired number of times in order to generate accurate pre-impact swing properties. The pre-impact swing properties are preferably based on about 1 or more swings of a golf club.
The golf ball properties that are determined include, but are not limited to, the coefficient of restitution of the ball at a plurality of velocities, the time of contact at a plurality of velocities, and the spin at a plurality of velocities and loft angles.
Additionally, the golf club properties that may be determined include the geometric center of the club face, the center of mass of the club head, the distance from the hosel to the center of mass of the club face and/or the center of mass of the club head, effective density of shaft material, the effective shear modulus for torsion about the shaft axis, the effective Young's modulus for the shaft material, and the outer and inner diameters of the shaft in two directions at the hosel end.
Thus, a golfer is only required to swing a golf club once to determine a predicted trajectory of the golf ball and the ball launch conditions. The predicted trajectory may include characteristics such as distance, flight path, landing position, final resting position, and the like. Moreover, the ball launch conditions may include the side spin, back spin, rifle spin, azimuth angle, launch angle, velocity, and the like.
The method described above may be performed using a computer program comprising computer instructions.
U.S. Pat. Nos. 6,241,622 and 6,488,591 are related patents disclosing a portable launch monitoring system that includes two cameras, strobe lights, beam splitters, reflective elements and reflective golf balls for recording images and determining the ball flight path in a pre-determined field-of-view.
U.S. Pat. Nos. 4,375,887 and 4,063,259 are related patents disclosing a launch monitoring system for measuring initial velocity, initial spin velocity, and launch angle to match a golfer's swing to a preferred golf ball having characteristics that best exploit the swing.
U.S. Pat. No. 4,160,942 discloses and optical object project used to display a simulation of a projected objected measured by a trajectory calculator including multiple cameras and data analysis.
U.S. Pat. Nos. 4,158,853 and 4,136,387 disclose a method for monitoring the flight of a golf ball (or any sports ball) post-launch preferably including multiple cameras and corresponding flash lamps triggered for measuring position, velocity and spin of a golf ball.
U.S. Pat. App. No. 20070032143 discloses a real time visual self-monitoring system including a camera and a monitor preferably mounted on the user's head.
U.S. Pat. App. Nos. 20070026975 and 20070026974 are by the same inventor and disclose a trajectory detection and feedback system using one or more cameras, an infrared emitter to illuminate a tracked object, and a data analysis for analyzing the recorded sequence of video to determine proper technique.
U.S. Pat. App. No. 20070010342 discloses a virtual model of a golf ball for simulating a trajectory and modeling a golf ball based on the virtual data.
U.S. Pat. App. No. 20040142772 discloses a measuring apparatus where the photographing is carried out from the back part by means of the first camera and the second camera and is carried out from the front part by means of the third camera. The position coordinates of the ball are calculated by a triangulation method based on image data obtained by the photographing from the back part and image data obtained by the photographing from the front part. The photographing to be carried out from the back part is relayed from the first camera to the second camera. The angle of view of the second camera is related to that of the first camera. Therefore, the ball can be photographed within a wide range of the trajectory through the relay.
The first camera should be positioned behind a ball launch point, the second camera should be positioned between the launch point and a drop point, and the third camera should be positioned before the drop point. Since the second camera is positioned between the launch point and the drop point, an angle formed by an optical axis in a horizontal direction can be set to be great. The angle of elevation of the golf ball measured immediately before the drop by means of the second camera is great. The measuring apparatus has high precision in the measurement of the ball immediately before the drop.
The angle of view of the first camera should partially overlap with that of the second camera. The angle of view of the second camera is related to that of the first camera based on ball images which are simultaneously photographed by the first camera and the second camera.
Other prior art refers to the use of a GPS system for measuring and displaying data:
U.S. Pat. No. 7,175,177 discloses a golf data management system including a PDA having a GPS and a processing unit that, among other things, provides individual player analysis based on data input by the player and data derived from a measuring unit based on the golf club used and the shot distance.
U.S. Pat. No. 7,118,498 discloses a portable GPS system for measuring and displaying distances between a golfer and an object, such as a target, based on golf course geographic information services. The system also provides a means for measuring data, such as wind direction and magnitude, along with elapsed time of play.
U.S. Pat. No. 7,095,312 discloses a portable GPS system for measuring and displaying attributes of a sports object, such as a golf ball, using an embedded electronic tracking device associated with each sport object.
U.S. Pat. No. 7,010,550 discloses a PDA for inputting, recording, and storing a player's hole-level and shot-level information. Data input may be off-line or on-line internet interactive.
U.S. Pat. No. 6,697,820 is a variation of U.S. Pat. No. 7,010,550 by the same inventor.
U.S. Pat. No. 6,585,609 discloses a scoring booklet related to a particular golf course. Each hole illustration is comprised of a grid corresponding to an interactive internet grid. The player indicates the golf ball location for each shot on the hole grid and then downloads the information to the interactive internet grid for historical data exchange based on previous golf rounds on the same course.
Still further, other prior art systems include:
Blackwell Synergy discloses a study measuring the movement path and speed of the clubhead as well as the clubface orientation and impact location during golf swing using 3D analysis video techniques.
IMAGO Video Trackers discloses a system for measuring the true trajectory of a golf ball by tracking the ball from launch to landing. This differs from previous systems that interpolate the ball flight by measuring the initial and landing ball positions.
NASAexplores discloses the use of high speed video equipment to capture a golf ball in flight. Computer hardware and software is used to analyze the measured spin rate and velocity of each ball resulting in a better designed golf ball.
Pitt Research discloses using advanced biomechanical assessment tools to measure rotation and velocity of the upper torso, pelvis and x-factor during a golf swing. Other measurements such as ball velocity and the relationship between biomechanical variables were assessed using a high speed eight camera 3D optical motion analysis system.
Sports Coach Systems discloses a simulator mat having an enclosed circuit board and including infrared technology to measure both the club and ball through the impact area.
Zelocity discloses a golf performance monitor that uses Doppler radar to measure the ball's velocity, spin and launch angle. Club head speed is also measured in the down swing and at impact.